The present invention relates to a slit valve closure useful, for example, in vacuum, semiconductor fabrication equipment.
During vacuum processing, the access openings to semiconductor vacuum fabrication chambers are closed and sealed by sliding or pivoting doors or closures. The closures may be operated (opened and closed) using various means such as, for example, pneumatic cylinders.
Compactness, high reliability and low cost are given requirements or disiderata of such closure mechanisms. With the increasing use of in-vacuum wafer-handling loadlock chamber which interface with an adjacent vacuum processing chamber for automatically loading wafers into the processing chamber and retrieving wafers from the chamber in vacuum, these requirements have become even more important, because the closure may be interposed between the loadlock chamber and the vacuum processing chamber and, in fact, may be located in the loadlock chamber. Quite obviously, when the closure is located in the loadlock it is highly desirable to minimize both its physical size and the space required for its opening/closing operation. This is true, particularly if the loadlock serves a multiple number of process chambers and, therefore, incorporates a number of closures. Of course, the use of multiple doors or closures increases the desirability of low unit cost. Furthermore, the high throughput goals of processing chambers (both single and multiple chamber systems) which use an automatic wafer-handling loadlock chamber require reliable closure operation.
Finally, but not exhaustively, particulates generated when even a single door or closure is located and operated within a vacuum loadlock chamber can have a drastic adverse impact on the operability of integrated circuits processed within the associated IC vacuum fabrication chamber (or within the loadlock chamber itself). As is well known in the industry, as the minimum feature sizes of integrated circuits are scaled downward from LSI (large scale integrated circuits) to VLSI (very large scale integrated circuits) and to even smaller sizes, the circuits become increasingly susceptible to damage by particulates.